Many products, such as automotive transmission housing and engine blocks, include precision bored holes. These holes are bored by cutting tools supported by a boring tool which is driven by a boring machine. In many situations, the boring machine is computer numerically controlled (CNC) for reasons of flexibility, economics, and precision. Many CNC boring machines are capable of performing a wide range of operations on a product, including the boring of many different sizes of holes, by the automatic selection of a previously adjusted boring tool from a tool bank.
However, many boring tools require manual adjustment by the machine operator. Some currently used boring tools, such as the 3F-HBD Boring and Facing Head by Criterion Machine Works of Costa Mesa, Calif.; and the tools of the Starflex Boring Tool Program of the Johne+ Company of Germany require manual adjustment of the position of the cutting tool corresponding to the desired bore diameter. Some tools include an internal worm gear adjustable by the operator with an Allen wrench to slide a tool holder within a groove of a machine coupling member. After the operator has manually positioned the cutting tool to bore the correct size diameter, the operator then tightens one or more fasteners to lock the position of the tool holder relative to the machine coupling element. Thus, the clamping force holding the cutting tool on the boring tool is not maintained during adjustment and the tool is reclamped after adjustment. This slow, inflexible, labor-intensive adjustment method detracts from the speed and economy of the CNC machine by requiring the operator to stop the operation of the CNC machine during the period of adjustment.
What is needed is a boring tool which permits adjustment of the position of the cutting tool by operation of the machine, and not by manual readjustment. Further, what is needed is a method of adjusting a boring tool on a CNC machine by software commands. The present invention overcomes the drawbacks of the related art in novel and unobvious? ways.